The purpose of the Core Lipid Laboratory (CLL) is to provide state of the art lipid analysis for the research projects. Discussion between a project investigator and the CLL Director will be held to decide which type of assay would be most suitable and the form in which the samples should be provided to the CLL. The CLL staff will carry out the analytical procedures and provide a written report containing the data as well as an interpretation of the results. Another function of the CLL is developmental. When new areas of investigation are instituted, the CLL will set up any new lipid procedures that will be required. This may involve selecting a procedure available from the literature or, if necessary, developing a new approach. In addition, the CLL will assist the research projects in designing experiments that require extensive lipid analysis. The procedures that will be offered on a routine basis include: 1) fatty acid compositional analysis by gas-lipid chromatography (GLC); 2) analysis of radioactive fatty acids by reverse phase high-performance liquid chromatography (HPLC); 3) chemical preparation of samples for fatty acid GLC and HPLC, including extraction of lipids from tissue or plasma samples, methylation, saponification, silylation, acetylation, and hydrogenation; 4) separation of phospholipids and neutral lipids by thin-layer chromatography (TLC); 5) phospholipid class separation by HPLC; 6) phospholipids molecular species determination by HLPC; 7) eicosanoid separations by HPLC; 8) chemical measurements of the phospholipid, cholesterol, triglyceride, and free fatty acid content; 9) lipid peroxidation, using the thiobarbituric acid reacting substances (TBARS) method for screening purposes, and where positive results are indicated, either ethane collection or lipid hydroperoxide (LOOH) determination by iodometric assay; 10) tocopherol assay by HPLC; and 11) identification of fatty acids and oxidation products by GLC combined with mass spectrometry (MS), negative ion chemical ionization (NICI-MS) to determine the molecular ion, and electron impact (EI-MS) to obtain further structural information.